Many-body dynamics of the decay of excitons of different charges in a quantum dot

We calculate the photoluminescence spectrum of a single semiconductor quantum dot strongly coupled to a continuum as a function of light frequency, gate voltage, and magnetic field. The spectrum is dominated by the recombination of several excitonic states which can be considered as quantum quenches in which the many-body nature of the system is suddenly changed between initial and final states. This is associated with an Anderson orthogonality catastrophe with a power-law singularity at the threshold. We explain the main features observed experimentally in the region of stability of the trion X-, the neutral exciton X0, and the gate-voltage-induced transition between them.Fil: Andrade Hoyos, Jhon Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Aligia, Armando Ángel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Cornaglia de la Cruz, Pablo Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentin

Os discursos dos meios de comunicação sobre o sujeito latino-americano na região da tríplice fronteira

Anais do V Encontro de Iniciação Científica e I Encontro Anual de Iniciação ao Desenvolvimento Tecnológico e Inovação – EICTI 2016 - 05 e 07 de outubro de 2016 – Sessão Linguística, Letras e ArtesNeste presente trabalho analisaremos como os discursos dos meios de comunicação agem na construção discursiva dos sujeitos na Tríplice Fronteira (Brasil, Argentina e Paraguai). O corpus observado constitui-se de alguns dos principais veículos de informações, tais como: os jornais, La jornada, El território, G1. A fim de compreender, em um primeiro momento, como se constituem os discursos acerca do termo Latino-Americano na fronteira. Em um segundo momento, abrimos espaço para analisar como aparece a questão indentitária na Tríplice Fronteira, uma vez, que através do termo Latino-Americano se expressa a identidade cultural da região. Um aspecto que analisamos foi a imigração dos Haitianos para a região oeste do Paraná, devido à sua incidência no período observado nos meios midiáticos do período selecionado. O trabalho desenvolvido pretende evidenciar através da Análise do Discurso a relevância da mídia e, de que forma, esta age sobre a formação discursiva e cultural da região

Expansion of CD34+ human hematopoietic cells from umbilical cord blood using roller bottles

"El transplante de células madre hematopoyéticas está limitado por la cantidad de células CD34+ presentes en las unidades de sangre de cordón umbilical; el objetivo de este trabajo fue obtener la expansión in vitro de células madre hematopoyéticas. Se establecieron cultivos de células CD34+ de sangre de cordón umbilical en medio IMDM suplementado con citocinas para promover la expansión de progenitores hematopoyéticos. En 5 días de cultivo en frascos giratorios se obtuvo la máxima expansión de unidades formadoras de colonias (UFC) totales de 16.94±2.82 veces, mientras que en cultivo estático fue de 17.28±4.47. La máxima expansión de células totales fue de 20.31±6.18 veces en frasco giratorio y de 26.45±9.89 veces en cultivo estático a los 10 días de cultivo. Se demostró la eficacia del sistema de frascos giratorios con medio IMDM para el cultivo a corto plazo de células enriquecidas CD34+ provenientes de sangre de cordón umbilical y para la expansión de progenitores hematopoyéticos, potencializando el uso de este sistema para otros experimentos y aplicaciones clínicas a futuro."Hematopoietic stem cell (HSC) transplantation is limited by the initial CD34+ cell content in cord blood units; the aim of this work was the in vitro expansion of HSC to overcome this issue. Supplemented IMDM roller bottle cultures of CD34+ cells from human umbilical cord blood were established for hematopoietic progenitor expansion. The maximum total colony forming cells (CFC) expansion was achieved after 5 days of culture, being 16.94±2.82 folds in roller bottles and 17.28±4.47 in static cultures. However, the maximum total cell fold expansion was attained after 10 days of culture. It was of 20.31±6.18 for the roller bottles and 26.45±9.89 for the static cultures. The efficacy of the roller bottles system for short-term cultures of CD34+ cells and expanding hematopoietic progenitors in IMDM was demonstrated; encouraging the use of this culture system for other experiments and may be used for future clinical applications.

Scaling of conductance through quantum dots with magnetic field

Using different techniques, and Fermi-liquid relationships, we calculate the variation with the applied magnetic field (up to second order) of the zero-temperature equilibrium conductance through a quantum dot described by the impurity Anderson model. We focus on the strong-coupling limit U, where U is the Coulomb repulsion and is half the resonant-level width, and consider several values of the dot level energy E d , ranging from the Kondo regime to the intermediate-valence regime F − E d ∼ , where F is the Fermi energy. We have mainly used the density-matrix renormalization group (DMRG) and the numerical renormalization group (NRG) combined with renormalized perturbation theory (RPT). Results for the dot occupancy and magnetic susceptibility from the DMRG and NRG + RPT are compared with the corresponding Bethe ansatz results for U → ∞, showing an excellent agreement once E d is renormalized by a constant Haldane shift. For U low-energy peak in the spectral density of the dot.Fil: Hamad, Ignacio Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Gazza, Claudio Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Andrade Hoyos, Jhon Alejandro. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Aligia, Armando Ángel. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cornaglia de la Cruz, Pablo Sebastian. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Roura Bas, Pablo Gines. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Information and Impression Regarding ASD Questionnaire Answered by Foreigners Living in Brazil

Autism Spectrum Disorders (ASDs) constitute a group of disorders characterized by changes present at early ages and manifesting in the areas of development of communication, behavior, and interpersonal relationship. Because ASD significantly affects communication and the social skills, all multicultural context needs to be better investigated. There is an urgent need to understand the impact of migratory process, bilingual environment exposure on the language development of children with ASD. The present study aims to present the results of 657 foreign residents in Brazil that answered an online questionnaire to know the consolidated information about ASD. Participants from 23 countries responded to the survey. Bolivia and Argentina were the countries with the highest number of participants. The present study found that 100% of the participants have heard of autism. About 80.6% of the sample had a family member with autism. The sociodemographic diversity identified in this study reflects the sociocultural diversity present in Brazil, besides reinforcing the importance of considering this population when thinking about strategies and behaviors directed at individuals with ASD

Ferromagnetic and underscreened Kondo behavior in quantum dot arrays

We analyze the low energy properties of a device with N + 1 quantum dots in a star configuration. A central quantum dot is tunnel coupled to source and drain electrodes and to N quantum dots. Extending previous results for the N = 2 case we show that, in the appropriate parameter regime, the low energy Hamiltonian of the system is a ferromagnetic Kondo model for a S = (N −1)/2 impurity spin. For small enough interdot tunnel coupling, however, a two-stage Kondo effect takes place as the temperature is decreased. The spin 1/2 in the central quantum dot is Kondo screened first and at lower temperatures the antiferromagnetic coupling to the side-coupled quantum dots leads to an underscreened S = N/2 Kondo effect. We present numerical results for the thermodynamic and spectral properties of the system which show a singular behavior at low temperatures and allow to characterize the different strongly correlated regimes of the device.Fil: Andrade Hoyos, Jhon Alejandro. Comisión Nacional de Energía Atómica. Gerencia del Área Investigaciones y Aplicaciones No Nucleares. Gerencia de Física (CAB). Grupo de Teoría de Sólidos; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Garcia, Daniel Julio. Comisión Nacional de Energía Atómica. Gerencia del Área Investigaciones y Aplicaciones No Nucleares. Gerencia de Física (CAB). Grupo de Teoría de Sólidos; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Cornaglia de la Cruz, Pablo Sebastian. Comisión Nacional de Energía Atómica. Gerencia del Área Investigaciones y Aplicaciones No Nucleares. Gerencia de Física (CAB). Grupo de Teoría de Sólidos; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentin

“La propuesta didáctica y su relación con el nivel de desarrollo del pensamiento crítico logrado, en estudiantes del cuarto año, de la facultad de administración de la Universidad Inca Garcilaso de la Vega-filial Chincha”

La investigación titulada “La propuesta didáctica y su relación con el nivel de desarrollo del pensamiento crítico logrado en estudiantes del cuarto año, de la Facultad de Administración de la Universidad Inca Garcilaso de la Vega-filial Chincha”, tuvo como propósito, determinar en qué medida se relaciona la propuesta didáctica planteada en la Universidad Inca Garcilaso de la Vega-filial Chincha y el nivel de desarrollo del pensamiento crítico logrado en estudiantes del cuarto año de la Facultad de Administración. Se estableció de manera general que existe una correlación estadísticamente significativa de 0.885; correlación positiva considerable entre las variables “Propuesta didáctica” y “Desarrollo del pensamiento crítico”. Asimismo, se determinó que el modelo didáctico y el pensamiento a nivel inferencial tienen una correlación estadísticamente significativa de 0.707, por lo que se determina que existe relación positiva alta entre las dimensiones. Por su parte, el Modelo Didáctico y el pensamiento a nivel crítico tienen una correlación estadísticamente significativa de 0.658, por lo cual se infiere l que existe relación positiva media entre las dimensiones descritas. Finalmente se estableció que los estilos de enseñanza y el pensamiento a nivel inferencial y el pensamiento a nivel crítico tienen una correlación estadísticamente significativa de 0.797 y 0.760, respectivamente, pudiéndose afirmar que existe relación positiva alta entre las dimensiones estudiadas.Tesi

Expansion of human hematopoietic cells from umbilical cord blood using roller bottles in CO2 and CO2-free atmosphere

"In this work, we evaluated the expansion of human hematopoietic stem cells from umbilical cord blood in roller bottles. The Iscove's modified Dulbecco's medium, the Stem Pro 34-SFM medium, and the L-15 Leibovitz's medium for cultures in CO2-free atmosphere were assessed. At day 5 of culture, total colony forming unit expansions of 14.44 ± 3.74, 11.20 ± 6.37, and 17.25 ± 3.65-folds were attained, respectively. The expansion reached using L-15 medium in roller bottles was around 10 times higher than that achieved in the static control cultures. To our knowledge, this is the first report of cultures in CO2-free atmosphere to expand cord blood human hematopoietic stem cells and it opens a new branch of possibilities for culturing and clinical applications.

The Covid-19 explosion in the state of Amapá: how is the most preserved region in the Brazilian Amazon currently fighting the SARS-COV 2 pandemic?

The state of Amapá is located in the extreme north of Brazil, within the Amazon rainforest and is crossed by the Equator. It has a hot and humid climate with rains that last 8 months a year and 4 months of unrelenting sun that melts rubber from car seals, fries eggs on the floor and even cooks a whole egg tub, in case you forget in a car exposed to the sun . It was believed that with this potent solar incidence, the Sars-COV 2 virus would not have so much impact in this region, a terrible mistake! Today Amapá has the highest incidence of Covid-19 in the whole of Brazil, with a maid of 600 cases per hundred thousand inhabitants and in the Amazon it is the 3rd in deaths and loses in this item only to the state of Amazonas and Pará.The state of Amapá is located in the extreme north of Brazil, within the Amazon rainforest and is crossed by the Equator. It has a hot and humid climate with rains that last 8 months a year and 4 months of unrelenting sun that melts rubber from car seals, fries eggs on the floor and even cooks a whole egg tub, in case you forget in a car exposed to the sun . It was believed that with this potent solar incidence, the Sars-COV 2 virus would not have so much impact in this region, a terrible mistake! Today Amapá has the highest incidence of Covid-19 in the whole of Brazil, with a maid of 600 cases per hundred thousand inhabitants and in the Amazon it is the 3rd in deaths and loses in this item only to the state of Amazonas and Pará